Advertisements
Advertisements
Question
Give reason.
Wasp sting is treated with vinegar.
Solution
Wasp stings are alkaline and they can be neutralized by vinegar which is a weak acid.
APPEARS IN
RELATED QUESTIONS
Fill in the blanK
A .............is a substance which changes the rate of a chemical reaction without undergoing a chemical change.
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer
Which of the following is a reducing agent?
- oxygen
- chlorine
- hydrogen
- none of these
FILL IN THE BLANK
On reaction with sulphuric acid solution, barium chloride forms a white precipitate of ........ sulphate.
FILL IN THE BLANK
Positively charged ions are called ........
TRUE \ FALSE
Positively charged electrode is called the anode. True or false ?
Explain the type of reactions on the basis of the direction of reaction.
How is a strong electrolyte different from a weak electrolyte?
State what you would observe when the following substance is heated in a glass test tube red lead.
Choose the correct option from the bracket and explain the statement giving reason.
(Oxidation, displacement, electrolysis, reduction, zinc, copper, double displacement, decomposition)
To prevent rusting, a layer of ______ metal is applied on iron sheets.
What is the reaction called when oxidation and reduction take place simultaneously? Explain with one example.
Match the pairs.
| a. | Photosynthesis | i. | Tendency to lose electrons |
| b. | Water | ii. | Reactant in combustion process |
| c. | Sodium chloride | iii. | Chemical change |
| d. | Dissolution of salt in water | iv. | Covalent bond |
| e. | Carbon | v. | Ionic bond |
| f. | Fluorine | vi. | Physical change |
| g. | Magnesium | vii. | Tendency to form anion |
Show with the help of diagram of electronic configuration how the following compound is formed from the constituent atoms.
Potassium fluoride
Complete the following table and write your observations.
|
Hydrogen sulphide |
Ammonia |
Sulphur dioxide |
Hydrogen chloride |
|
|
Shake the gas with red litmus solution |
||||
|
Shake the gas with blue litmus solution |
||||
|
Apply a burning splint to a gas |
Give a word equation for the following reaction.
An exothermic reaction where both the reactants are gases, one of which is oxygen.
What is a chemical reaction?
Complete the table given below.
| Addition of dil. H2SO4 to KHCO3 | Name of residue obtained |
NPK are the primary nutrients for plants.
What is the role of a catalyst in a chemical reaction?
Which of the following is not an “element + element → compound” type reaction?
A reaction between an acid and a base is called ______.
Anaerobic bacteria digest animal waste and produce biogas (Change – A). The biogas is then burnt as fuel (Change – B). The following statements pertain to these changes. Choose the correct one.
Chemists identify gypsum as a natural indicator.
The water we drink is a combination of hydrogen and oxygen.
Give an example of a chemical reaction for each of the following situations:
A change in colour is observed.
A student took a solution of copper sulphate in a beaker and put a clean iron nail into it and left it for about an hour.
What changes do you expect?
Vanaspati is obtained from vegetable oils by the addition of ______ to the oils.
Write the equation for the process of formation of rust.
When milk is mixed with coffee decoction, the colour of milk and decoction changes due to ______.
